1. Field of the Invention
This invention relates in general to the construction of thermal drilling devices and in particular to a new and useful drill particularly for drilling geological formations which includes means for generating gaseous products of combustion in an interior combustion chamber of the drill and for discharging them through a nozzle having a slot discharge opening.
2. Description of the Prior Art
Various thermal drive devices are known for drill constructions. They comprise substantially a combustion chamber into which mostly liquid fuel and oxygen are fed and which react to produce hot drilling gases and they include a discharge nozzle for the hot drilling gases which is provided downstream of the combustion chamber and which has a circular cross-section. In addition they include means for accommodating a water cooling system and in some cases additional mechanical drilling heads with cutting tools for reaming the thermally rough drilled hole and finally means for supplying the operating fluids. With such devices the drilling is effected so that the hot drilling jet melts or cleaves the rock by the applied heat while the water which is simultaneously applied is vaporized and the steam under pressure entrains the drillings upwardly.